Known from U.S. Pat. No. 4,754,388 is one such voltage regulator circuit. This voltage regulator circuit contains in the series branch ahead of the actual series regulator a transistor circuit which acts as a switch and interrupts the current flowing to the series regulator as soon as the input voltage exceeds a predetermined value. Interrupting the current may result in high current and voltage peaks in the circuit, requiring the circuit to include components capable of withstanding these high current and voltage peaks.